Water-heater construction.



P. L. 0. WADSWORTH.

WATER HEATER CONSTRUCTION.

APPLICATION FILED NOV. 10, 1911.

1 1 08,2845, Patented. Aug. 25, WM,

SSHEETS-SHEET l.

F. L. O. WADSWORTH. WATER HEATER CONSTRUCTION.

APPLICATION FILED NOV. 10, 1911.

1,1O8,28 lk. Patented Aug". 25, 19M,

3 SHEETS SHEBT Z.

WITNESSEL? NVENTQW Mam F. L. 0., WADSWORTH.

WATER HEATER CONSTRUCTION.

APPLICATION FILED NOV. 10,

Patented Aug. 25, 19M

INVENTOR UNITED STATES PATENT OFFICE.

I FRANK L. 0. WAIbSWORTH, F SEWICILEY, PENNSYLVANIA.

WATER-HEATER CONSTRUCTION.

To all whom it may concern:

Be, it known that I, FRANK L. O. WADS- woRTn, a citizen of the United States, residing at Sewickley, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in ater-Heater Construction, of which the following is a specification.

My invention relates to automatic control apparatus for hot water heaters, particularly of the so-called instantaneous type, in which fuel is automatically supplied to and cut oil from the main burners oi? the heater concurrently with the turning bn and shutting cit of the flow or water through the heating coils. Some oi the particular objects of my invention are; the control of the fuel supply by the movements of a single valve which is held to its seat at all times save when there is an actual flow of water through the heater coils; the provision of means whereby said valve is moved solely by the action of the thermostatically controlled parts; and the provision of means whereby the thermostatic control mecha nism is brought into operative relationship only when water is flowing through the heater.

Other objects of my invention will appear hereafter.

lln the drawings which form a part of this specification;

Figures 1 and 2 illustrate in side and front elevation respectively an ordinary form of instantaneous hot water heater provided with one type of my improved automatic control apparatus; Fig. 8 in cross-section on an enlarged scale the control mechanism of Figs. 1 and 2; l igs. i, 5 and ll illustrate modifications of one part oi. the control mechanism shown in Figs. 1, and and Figs. 7, 8 and 9 illustrate other forms of controls which also embody my invention.

Referring first to the general arrange ment of the heater parts as shown in Figs. 1 and 2; A is the casing of the heater; B and C are the upper coils of the heater; D is the lower reverse coil of the heater connected to the upper coils by. means of the pipe E; F are the burners mounted upon the usual burner ring; G- is the gas supply pipe leading to the casing H of the gas valve; 1 the pipe leading from the valve casing to the burner ring, and J is the mechanism for automatically controlling the Specification of Letters Patent.

Application filed November 10, 1811.

illustrates Patented Aug. 25, 1914. Serial No. 669,546.

position of the gas valve and the flow of gas to the burners. that the showing of the heater itself is a conventional one and that the invention resides particularly in the controlling mechanism which is readily applicable to types of heater other than the one illustrated.

Referring now to Fig. 3 in connection with Figs. 1 and 2; 1 indicates the supply pipe leading from the cold water main to the front or lower end of a cylinder 2 which contains. the water actuated piston member 3; 4 indicates the passage-way leading to the upper end of the heater coils; and 5 indicates the outlet from the lower reverse coil of the heater. Ojn'the lower head of the cylinder 2 I provide an upwardly projecting hollow boss 6, and on the lower side of the piston member 3 I provide a downwardly projecting hollow boss 7 which, when the piston member is in its lowest closed or inoperative position, fits down into the opening in the boss 6, and closes oli' communica tion between the inlet passage 1 and the outlet 4 which leads to the top of the heater coils. The inner surface of the boss 6 is provided with a series of tapered grooves e8, so that when the piston member 8 is lifted, a passage-way or gradually increas ing cross-section is provided for the flow ofthe liquid from the pipe 1 to the heater in It will be understood let The lower end of the boss 7 is per- I iorated tor a purpose presently to be described, and secured in it is a stem 9 which passes down through a stu'l'lingbox 10 on. the lower head oi the cylinder, and is secured to a tension member 11. A flexible washer 12 is secured to the lower end of the boss 7 and is held tightly against the opposing race oi the cylinder 2-when the piston 3 is in its lowest position by means of a shin 13 so that in the closed )osition'oii l 2: a l

the water actuated member, the opening around the stem 9 is sealed and leakage oi liquid past that stem is thereby prevented even though the stuilingbox 10 may be loose. The water after flowing through the heater coils and emerging from the outlet 5 enters the lower end of a thermostat chamber 14 and passes upward to an outlet pipe 15 which communicates. with the house supply system.- At the upper end of this thermostat chamber there is a lateral port 'IGwhich enters theupper end-of the cylinder 2. The rear or upper end ot the boss 7 is bored to receive a cylindrical valve member 17 which is adjustably secured in position to the upper head 18 of the cylinder 2 by means of a nut 19, and which is provided at its lower end with port slots 20 that afford communication between the upper end of the cylinder 2 and the central opening in the boss 7 L A single thermostat member 21 consisting of a hollow tapered tube of copper, brass, zinc or some other material having a high coefficient of expansion, is secured to a boss 22 at the upper end of the thermostat chamber and terminates at its lower end in a perforated head 23 which carries a stud 24 projecting through the cap 25 at the lower end of the thermostat chamber 14. In order to avoid the use of a stuffing box around this stud I provide a rubber tube 26 which issecured at its lower end to an upwardly projecting boss on the cap 25 and at its upper end to the head 23. This tube has sufficient longitudinal flexibility to permit of the necessary expansion and contraction of the thermostat member 21 while hermetically sealing the opening around the stud 24 and preventing leaKage of liquid through the stud opening in the cap 25. The stud 24 terminates in a knife edge which is adapted to engage with a thermostat lever 27, this thermostat lever being mounted on two adjustable screws 28one behind, and the other in front of the sectional plane of Fig. 3and carries at its outer end a link 29 to which is secured the lower end of a spring 30, the upper end of said spring being in turn connected to a tension member 11. The flow of gas from the fuel supply pipe to the feed pipe which leads to the main burners of the heater via the pipes G and I, is controlled by a gas valve 31 which is normally held seated by a weight 32, and is provided with a stem 33 leading upward through the cap 34 on the gas valve chamber and terminating in a fork 35 carrying an lever 27 is consequently held by its ownv weight out of operative engagement with the thermostat parts, so that no I movement of those partseither of expansion or con- 3, and the greater pressure of the infiowing water on the lower side of that piston will lift it, thus opening a passage-way through the ports 8 to the inlet 4. The tapered form of these ports necessitates a considerable vertioalmovement of-the piston member in order to afford a sufficient port opening for the continuous supply of liquid to the eater coils to take the place of that withdrawn from the pipe 15. The first upward movement of the piston member 3 closes the port openings 20 around the stem 17 and thus compels all of the liquid which flows in through the pipe 1 to pass through the coil inlet 4 and flow through the heating coils. The upward movement of the piston stretches the spring 30 and lifts the thermostat lever 27 into operative engagement with the stud 24 which is secured to the thermostat member 21. The position of this stud is determined by the temperature of the liquid in the thermostat chamber, and if this temperature is below the point at which the mechanism is adjusted to cut off the supply of fuel to the main burners, the spring 30-when placed under tension by the upward movement of the piston member 3will lift the gas valve 31 from its seat and allow fuel to flow through the gas valve chamber from the inlet pipe to the outlet pipe. But as soon as the temperature of the flowing liquid has reached a predetermined pointwhich is determined by the adjustment of the screw 36the expansion of the thermostat element 21 will depress the stud 24 sufficiently to release the gas valve 31 from the tension of the spring 30, and the said gas Valve will be closed by the weight 32, thus shutting oh the flow of fuel to the main burners of the heater. The immediate reduction in the temperature of the flowing water, and the consequent contraction of the thermostat member 21 will again lift the stud 24 and subject the gas valve once more to the tension of the spring 30, which will again lift it from its seat and reestablish the flow of fuel through the gas valve chamber. These successive actions which result in'the closing and opening of the fuel valve 31 will continue with each successive elevation and depression of the temperature of the flowing liquid above and below the point at which the thermostat may be said to act, as long as water continues to flow through the apparatus. When the flow of water is shut ofi, the piston member 3 will be returned to its lowest position partly by the tension of the spring 30 and partly by the weight of the piston member 3 itself; and the return of said piston member to the closed position finally relieves the spring 30 of all'tension, thereby allowing the thermostat lever 27 to drop out of operative relationship with the other parts of the mechanism so that no movements of the thermoof the water actuated member, affect in any I as way the position of the gas valve 31. If necessary, an auxiliary spring may be inte'rpo'sed between the piston member 3 and the upper head" 18 to assist the water actuatedmember 3 in its return to its lowest position.

In the position shown in Fig. 3, the port opening 20 will be always opened thus affording a free communication between the upper end of the thermostat chamber '14- (and the upper end of the cylinder 2) and the passage leading to the inlet 4, and thus providing for a free circulation of liquid between the inlet and outlet of the heater coils under the heating influence of the pilot light.

Figs. 4, 5 and 6 illustrate merely modififications in the construction of the thermostat member 21. In the construction shown in Figs. 4- and 5 the thermostat member consists of a nest of tubes 41, which are preferably made of iron, steel, lnvar metal, or some other material having a comparatively low coe'flicient of expansion closed at both their'upper and lower ends byflheads 42 and 43 and filled with liquid such asv alcohol, ether, petroleum oil, or other fluid having a high coefficient of expansion, or with paraflin or fusible metal which melts and becomes liquid at a temperature less than that for which the thermostat element may designed to act. The lower head 43 is hollow and is provided with a diaphragm box member a l, the interior of which is in communication with the hollow head 43 and the tubes ll connected thereto. This diaphragm box member 44 carries at its lower- 27 mounted on pivot screw supports l5 so as to occupy the same relation to the other parts of the mechanism as is illustrated in Fig. 3.

Tn the construction of Fig. 6, the then inostat element is of the usual composite construction comprising an outer tapered tube 21 of copper, brass, zinc, or some other metal having a high coefficient of expansion, and an inner rod 46 of iron, steel, lfnvar metal or similar material having a low coefficient of expansion; the two elements 21 and 46 being rigidly secured to a common water tight ca 4:? at the closed upper end of the composite thermostat element. The inner element 46 passes down through an opening in the cap 47 to which the lower end of the tube 21' is secured, and terminates in a loop 48 which loosely embraces the end of the thermostat lever 27 and is adapted to engage therewith through the medium of two adjustable screws 49, one of WllilCll-2LS shownds located behind the cross-sectional plane of Fig. l, and the other '3 of which is in front of that plane; the thermostat lever 27' being in this case pivoted on a single central screw 50 symmetrically located between the planes of engagement of the two screws 49. The other parts of the mechanism are of the same construction and are arranged in the same way as shown in Fig. 3, the reversal of the thermostat supports being necessary because of the fact that the heating of the tube 21' permits the arm 27 to move upward instead of downward as is the case in the arm 27 of Fig. 3 when the tube 21 is heated. The general mode of operation of the mechanism illustrated in each of the Figs. 3, 4, 5 and 6 is substantially the same.

Fig, 7 illustrates a construction resembling in many respects the construction of Fig. 3, but differing therefrom in certain details relating principally to the form of the water actuated element. In this figure 1, indicates the cold water supply pipe, which in this case communicates directly with the inlet a to the heater coils. A port 51 leads from the cold water inlet to the upper end of the cylinder 2 which contains the water actuated piston member 3. The water after passing through the heater coils emerges from the outlet 5 and enters the lower end of a pipe 52 which leads upwardly to the thermostat chamber l l. A port 53 leads from this chamber to the space below the piston member 3, which inthis case is actuated solely by difi'erential pressures as will be presently explained. The piston member 3 is provided with a stem 9 which passes upwardly through the top wall of the cylinder 2 and terminates in a head 54.

on which rests a weight The weight isprovidcd with a fork 56 which carries an adjust-able screw 57, said screw being adapted to engage a lever 59 that is pivoted on screws 60 and projects at its other end into the thermostat chamber l4; This left hand projecting portion of this lever 59 passes "to the gas valve 31' and fork 61 and serve to seal the opening around the stem 33 when thegas valve is in its opened position, and the opening around the stem 62 when said valve is in its closed position The thermostat member which I illustrate in this figure, consists of a flat disk shaped chamber 65 mounted on a cap 66 which closes the upper end of the thermostat chamber M. The interior the upper thermostat chamber 14.

opening of the disk shaped chamber 65 is filled with some liquid having a high coefiicient of expansion, and preferably having a considerable viscosity such as petroleum oil or mercury, or with a material like paraffin or fusible metal which is solid at low temperatures but melts at a temperature less than that for which the thermostat is designed to act. The lower head of the chamber 65 is provided with a central sleeve or tube 67 in which is accurately fitted a plunger 68, which may be provided with any suitable packing means (not shown) and the end of this plunger terminates in a knife edge which is adapted to engage with the extreme left hand end of the lever 59. A tightly fitted and packed screw 69 affords means for filling the thermostat 65, and also for varying the interior volume of said thermostat chamber. The upper end of the water actuated piston stem 9 is shouldered to engage with a poppet valve head 70 wh ch, when the piston member 3' is 1n its ralsed or closed position, is lifted to uncover the port opening 71 and thus affords free communication between the liquid on the upper side of the piston member and the liquidniln Tspring 72 interposed between the head 70 and the head 54 serves to keep this valve seated and close off the opening to the port 71 when the piston member 3 is lowered. A pipe 15 leads from the upper part of the thermostat chamber 14/ to the house supply system.

The operation of the mechanism shown in Fig. 7 is as follows: When there is no liquid in the apparatus, or when it is filled with liquid at rest, the piston member 3 is held in its elevated position by means of a spring 78, the tension of which is sufficient to lift the weight 55 and hold the screw 57 out of engagement with the end of the lever 59. In this position of the parts, the stem 62 which leads to the gas valve 31 is relieved of all tension, and no action of the thermostat can aflect in any way the movement of said gas valve, which is held to its seat by its own weight. But as soon as a flow of water is started through the heater, the two sides of the piston member 3 will be subjected to a differential pressure produced by the resistance of the flow of the liquid through the heater coils and the parts are so proportioned that under this difierence of pressure the piston member 3 will be depressed, compressing the spring 73-and later the spring 7 2thus allowing the weight 55 to act upon the lever 59. If the temperature of the liquid in the thermostat chamber 14' is less than that for which the thermostat is designed to actas determined by the adjustment of either the sleeve 64 or the screw 69 the left hand end of the lever 59 will be raised by the weight 55 thus opening the gas 'valve 31' and allowing fuel to flow from the supply pipe to the feed pipe, which commue' nicates with the main burners of the heater. This valve will remain open until the temperature in the thermostat chamber 14 reaches such a point that the expansion of the liquid in the thermostat box 65 forces the plunger 68 into contact With the left hand end of the lever 59 and thereby lifts the weight 55 and relieves the stem 62 from the pull of this weight. The gas valve 31 will then close under its own weight-supplemented, if desired, by the action of another weight or spring-thereby shutting 01? the supply of fuel to the main burners'of the heater. The continued flow of water through the apparatus will reduce the temperature in the thermostat chamber 14'- with the corresponding contraction of the liquid in the thermostat box 65and this will result in a retraction of the plunger 68, thus permitting the weight 55 to once more act on the stem 62 and open the gas valve 81. These alternate opening and closing movements of the gas valve under the joint control of the weight 55 and thermostat will continue with the successive depression and elevation of the temperature of the flowing liquid below and above the point of thermostatic control as long as liquid continues to flow through the heater. But as soon as the flow of liquid is stopped, the pressures on the two sides of the water actuated member 3 are equalized, and this member is then lifted by the action of the spring 73, and the lever 59 is relieved from the controlling influence of the weight 55, thereby freeing the stem 62 from all control and preventing any further movement of the gas valve until the parts have once more been brought into operative relationship by again establishing a flowv of liquid through the apparatus.

As in the previous case, the return of the Water actuated member 3 to its closed or inoperative position opens the port communications between the water on the inlet side of the piston and the water on the outlet side of the heater and permits of a free circulation of the liquid through the heater coils under the influence of the pilot light.

Fig. 8 illustrated another embodiment of my invention in which the construction and arrangement of parts is somewhat different than in the preceding figures. In this apparatus 1 indicates the pipe through which cold water is supplied to the heater, 3 indicates-the water actuated member, which in thls case is in the'form of a poppet valve normally held to its seat by a spring 75, and 7 6 indicates a connection leading from the space above the said water valve to the cold water inlet (not shown) at the top of the heater coil. After passing through the heater, the water emerges as before from an endof the spring member 99 bears against a collar 102 carrying a stud 103, which is adapted to engage with the upper recessed end of a lever 104. This lever 104 is ivoted on supporting screws- 105 in the sides of the box 93 and its lower end terminates opposite a short stud or stem 62 which passes through a stuifing box 63 and engages with an adjustable-head 64 on the outer end of the gas valve stem 33 The said gas valve stem passes through a suitable stuffing box in the front wall of the gas valve chamber containing the gas valve 31 which is normally held to its seat by a spring 106 and controls the flow of gast i rough the pipes G and l to the burners. The lower portion of the. water chamber or casing is separated in part from the upper portion by a partition wall 107,-.and in this lower portion, just opposite the hot water inlet port 94: is located the thermostat element 14 which in this case consists of a single corrugated tube closed at both ends and, filled as before with some liquidhaving a high coefiicient of expansion, or with some material like parafiin or fusible metal which is ordinarily solid, but which becomes liquid at a temperature less than that at which the thermostatic control mechanism is designed to act. The front head of the thermostat memberl i is provided with a stud 108 which is supported in position in a recess in the lever 107.

- The operation of this mechanism is as follows: "When no liquid is flowing through the apparatus, the water actuated member 96 is maintained in the position shown in. the figure by its own elasticity, and as in this position the spring member 99 is free from tensionvthe gas valve member 31 will alwaysbe held closed by the tension of the spring 106. But as soon as a flow of water is started through the heater, the pressure of the liquid in the chamber 93 is reduced by the withdrawal of water through the house service pipe 15 and by the resistance to the flow of the water through the heater coils. The pressure on the inside of the corrugated diaphragm member 96which communicates through the ports 51 with the inflowing water-is then greater'than the pressure on the outside of said diaphragm member and the latter is correspondingly expanded moving the head 98 to the right. The first initial movement of this head releases the collar 100 from the stud 101 and closes the port openings 110 around the end of this collar thereby preventing any further direct movement of the liquid from one side of the diaphragm member to the other. The movement of the head 98 to the right also places the spring member 99 under compression tension, thus forcing the stud 103 into operative engagement with the lever 104;. If at this time the flowing liquid is cold, the thering fuel to flow from the supply pipe to the feed pipe and thence on to the main burners of the heater. This flow of fuel will continue until the temperature of thefiowing liquid has suificiently expanded the thermostat member 14: to bring the stud 108 into engagement with the lever 104; and move the lower end of the latter far enough to the right to free the gas valve from the controlling influence of the spring member 99. The gas valve will then be closed by the action of the spring 106, and will remain closed until the thermostat 14 has again contracted sufiiciently to allow the gas valve parts to be brought once more under the controlling influence of the spring member 99. The successive opening and closing movements of the valve 31 under the control of the spring member-99 is determined by the contraction and expansion of the thermostat member 14 and will continue as the temperature of the flowing liquid falls and rises alternately below and above the temperature at which the thermostat may be set to act, this point of: thermostatic oontrol being varied by. the adjustment of the screw nut 64". When the flow of water is shut oil? the pressure on the inside and outside of the diaphragm box 96 is equalized, and said box will contract to its original position shown in Fig. 9 by virtue of its own elasticity, thereby relieving the spring 99 of any compression tension and correspondingly freeing the lever 104 from any controlling influence of either the spring member or of the thermostat parts. When the member 96. has returned to its normal unexpanded condition, the ports 110 will be opened by the contact of the stud 101 with the perforated collar 100 and a free communication will be established between the inlet and outlet of the heater coils, thus permitting water to'circulate therein under the influence of the still burning pilot light.

It will be obvious to those skilled in the art that various detail changes and modifications in construction may be made in any of the above described forms of mechanism without departing from my invention.

Thus, for, example, in the form illustrated mo est ments one for another will also readily suggest themselves in various adaptations of the incchamsm to different constructions.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is the following I 1. In combination in an instantaneous water heater, a water actuated member operated by opening and closing the outlet from the heater, a gas valve yieldingly" maintained in closed position when not acted upon externally, a thermostat controlled by the water of the heater, a controlling lever tor the gas valve intermediate the water actuated member and the gas valve, a resilient connection between the controlling member'and water actuated member Whereby the controlling lever is moved by the water actuated member to open the gas valve when the outlet from the heater is opened, and an operative connection between the thermostat and controlling lever, whereby such lever is held against movement by the Water actuated member tending to open the gas ,valve when the temperature of the water is above a predetermined point, and whereby such lever is permitted to be moved by the water actuated member to a position to open the gas valve when the temperature of the water is below such predetermined point.

9. In combination in an instantaneous water heater, :1. water actuated member operated by opening and closing the outlet from the heater, a gas valve yieldingly maintained in closed position when not acted upon externally, a thermostat controlled by the water of the heater, a controlling lever for the gas valve intermediate the water actuated member and the gas valve, a resilient connection between the controlling member and water actuated member whereby the controlling lever is moved by the water actuated member to open the gas valve when the outlet from the heater is opened, and/an operative connection between the thermostat and controlling lever whereby such lever is moved to a position to secure the closure of the gas valve against the force of the said resilient connection when the outlet from the heater is open and the temperature of the water in the heater rises above a predetermined point for which the thermostat is set and whereby the said lever is permitted to be moved by the water actuated member to a position to open the gas valve when the temperature of the water is below such predetermined point.

- 3.1a combinationin an instantaneous water heater, a water actuated member operated by opening and closing the outlet from the heater, a gas valve yieldingly maintained in closed position when not acted upon externally, a thermostat controlled by the water in the heater, a controlling member for the gas valve, a resilient connection between the controlling member and water actuated member whereby the controlling member is moved in one direction by the water actuated member to open the gas valve when the outlet from the heater is opened, and a direct connectionbetween the controlling member and thermostat for moving the said controlling member in the other direction to secure the closure of the gas valve against the force of the said resilient connection when the temperature of the water in the heater rises above a prede termined point,

4;. in combination in an instantaneous water heater, a water actuated member open atedby opening and closingthe outlet from the heater, a gas valve yielclingly maintained in closed position when not acted upon externally, an expansible member acted upon by the water of the heater, a controlling member for the gas valve, a resilient connection between the controlling member and the water actuated member whereby the controlling member is moved in one direction by the water actuated member to open the gas valve when the outlet from the heater is opened, and means carried by the eXpa-nsible member for directly and positively moving the controlling member in the other direction to secure the closure of the gas valve against the force of the said re silient connection when the temperature of the water in the heater rises above a predetermined point.

5. in combination in. an instantaneous water heater, a water actuated member operated by opening-and closing the outlet from the heater, a gas valve yieldingly maintained in closed position when not actuated upon externally, a controlling member tor the valve, a resilient connection between the controlling member and the water actuated member whereby the controlling memher is moved in one direction by the water actuated member to open the gas valve when the outlet'trom the heater is opened, and an expansible member acted upon by the water of the heater and carrying means engaging the controlling member for positively moving such controlling member reversely and in the direction of the expansion of the expansible member to secure the closure of the gas valve against the force of the said resilient connection when the temperature of the water in the heater rises above a predetermined point.

6, In combination in an instantaneous water heater, a water actuated member op-' erated by opening and closing the outlet from the heater, a gas valve yieldingly maintained in closed position when not acted upon externally, a thermostat controlled by the water of the heater, a controlling member for the gas valve, a yielding tension connection between the controlling member and water actuated member whereby the controlling member is moved in one direction by the water actuated member to .pull open the'ga-s valve when the outlet from the heater is opened, and a direct connection between the controlling member and thermostat for moving the said controlling member in the other direction to secure the closure of the gas valve against the force of the said resilient connection when the temperature of the water in the heater rises above a predetermined point.

7. In combination in an instantaneous Water heater, a water actuated member operated by opening and closing the outlet from the heater, a'gas valve yieldingly maintained in closed position when not acted upon externally, a thermostat controlled by Y the water in the heater, a controlling lever,

a connection therefrom to the gas valve, a resilient connection between the lever and the water actuated member whereby a movement of the controlling lever 1s secured by the movement of the water actuated member to open the gas valve when the outlet from the heater is opened, and a positive connection between the lever and thermostat whereby the lever is moved to a position to secure the closure of the gas valve against the forceof the said resilient connection T ing means therefor, a connection between the controlling member and water actuated member so arranged that a movement of the water actuated member secures the application of the stress applying means to the controlling member and an opening of the gas valve, but at the same time permits a movement of the controlling member in the reverse direction without moving the water actuated member, a direct connection between the controlling member and thermostat for moving the said controlling member to secure the closure of the gas valve when the temperature of the water in the heater rises above a predetermined point.

9. In combination in an instantaneous water heater, a, water actuated member operated by opening and closing the outlet from the heater, a gas valve yieldingly maintained in closed position when not acted upon externally, a thermostat controlled by the water of the heater, a connection between the gas valve and thermostat having lost motion when the water of the heater is below a predetermined point and the outlet from the heater is closed, and means controlled by the movement of the water valve for taking up the lost motion between the thermostat and gas valve and placing such connection under stress tending to open the gas valve when the outlet from the heater is opened, the said thermostat being arranged so that it acts positively to overcome the said stress when the temperature of the water heater rises above a predetermined point.

10. In combination in an instantaneous water heater, a water actuated member operated by opening and closing the outlet from the heater, a gas valve yieldingly maintained in closed position when not acted upon externally, a thermostatcontrolled by the water of the heater, a connection between the gas valve and thermostat having lost motion when the water of the heater is below a predetermined point and the outlet from the heater is closed, and means controlled by the movement of the water valve for taking up the lost motion between the thermostat and gas valve and placing such connection under a yielding force tending to open the gas valve when the outlet from the heater is opened.

l1. In combination in an instantaneous water heater, a water actuated member operated by opening and closing the outlet from the heater, a gas valve yieldingly maintained inclosed position when not acted upon externally, a thermostat controlled by the water of the heater, a connecting means between the gas valve and thermostat having lost motion when the water valve is in inoperative position, and means controlled by the water actuated member and arranged to apply a yielding force to take up the lost motion in the said connecting means and to operate the said connecting means to open the gas valve when the outlet of the heater is opened and the temperature of the water in the heater is below into operative connection with the connecting member and subject the latter to actuatingstress when water is flowing through the heater, and to 'free the said gas valve and thermostat and-the'connecting member from operative relationship when the water is at rest.

13. lm'combination in an instantaneous water heater, a water actuated member operated-by' opening "and closing the outlet from the; heater, a gas valve yieldingly maintained in closed position when not acted upon" externally, a thermostat con- "trolledby the'water of the heater, a connecting member between the gas valve and thermostat whichis normally out of operative contact with both the gas valve and thermostat, and a variable strain member interposed between the water actuated member and the said connecting member and adapted to'bring the thermostat and gas valve into operative relationship with each other when water is flowing, and release such parts from actuating stress when the Water is at rest.

14. In combination in an instantaneous water heater, a water actuated member operated by opening and closing the outlet from. the heater, 3, gas valve yieldingly maintained in closed position when not acted upon externall' a thermostat controlled b the water 6 the heater, a connecting mem er between the thermostat and gas valve'which is normally free from any operative stress when the water is at rest, and a strain member interposed between the water actuated member and connecting member and adapted to place the latter under operative stress only when the water is flowing through theheater.

In testimony whereof I have hereunto signed my name in the presence of the two subscribed witnesses.

FRANK L. O. WADSWORTH. Vv itnesses:

Ln'rrrm A. MYERS,

Doeume BELLINGER. 

